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IETF IDN Working Group Sung Jae Shim
Internet Draft DualName, Inc.
Document: draft-ietf-idn-vidn-01.txt 2 March 2001
Expires: 2 September 2001
Virtually Internationalized Domain Names (VIDN)
Status of this Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Task Force
(IETF), its areas, and its working groups. Note that other groups may also
distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months and may be
updated, replaced, or obsoleted by other documents at any time. It is
inappropriate to use Internet-Drafts as reference material or to cite them other
than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
1. Abstract
This document proposes a method that enables domain names to be used in both
local and English scripts, as a directory-search solution at an upper layer
above the DNS. The method first converts virtual domain names typed in local
scripts into the corresponding domain names in English scripts that comply with
the DNS, using the knowledge of transliteration between local and English
scripts. Then, the method searches for and displays domain names in English
scripts that are active on the Internet so that the user can choose any of them.
The conversion takes place automatically and transparently in the user's
applications before DNS queries are sent, and so, the method does not make any
change to the DNS nor require separate name servers.
2. Conventions and definitions used in this document
The key words "REQUIRED" and "MAY" in this document are to be interpreted as
described in RFC-2119 [1].
A "host" is a computer or device attached to the Internet. A "user host" is a
computer or device with which a user is connected to the Internet, and a "user"
is a person who uses a user host. A "server host" is a computer or device that
provides services to user hosts.
An "entity" is an organization or individual that has a domain name registered
with the DNS.
A "local language" is a language other than English language that a user prefers
to use in a local context. "Local scripts" are scripts of a local language and
"English scripts" are scripts of English language.
A "virtual domain name" is a domain name in local scripts, and it is not
registered with the DNS but used for the convenience of users. An "English
domain name" is a domain name in English scripts. A "domain name" refers to an
English domain name that complies with the DNS, unless specified otherwise.
A "coded portion" is a pre-coded portion of a domain name (e.g., generic codes
including 'com', 'edu', 'gov', 'int', 'mil', 'net', 'org', and country codes
such as 'kr', 'jp', 'cn', and so on). An "entity-defined portion" is a portion
of a domain name, which is defined by the entity that holds the domain name
(e.g., host name, organization name, server name, and so on).
The method proposed in this document is called "virtually internationalized
domain names (VIDN)," as it enables domain names in English scripts to be used
virtually in local scripts.
A number of Korean-language characters are used in the original of this document
for examples, which is available from the author upon request. The software used
for Internet-Drafts does not allow using multilingual characters other than
ASCII characters. Thus, this document may not display Korean-language characters
properly, although it may be comprehensible without the examples using Korean-
language characters. Also, when you open the original of this document, please
select your view encoding type to Korean for Korean-language characters to be
displayed properly.
3. Introduction
Domain names are valuable to Internet users as a main identifier of entities and
resources on the Internet. The DNS allows using only English scripts in naming
hosts or clusters of hosts on the Internet. More specifically, the DNS uses only
the basic Latin alphabets (case-insensitive), the decimal digits (0-9) and the
hyphen (-) in domain names. But there is a growing need for internationalized
domain names in local scripts. Recognizing this need, various methods have been
proposed to use local scripts in domain names. But to date, no method appears to
meet all the requirements of internationalized domain names as described in
Wenzel and Seng [2].
A group of earlier methods tries to put internationalized domain names in local
scripts inside some parts of the overall DNS, using special encoding schemes of
Universal Character Set (UCS). But these methods put too much of a burden on the
DNS, requiring a great deal of work for transition and update of the DNS
components and the applications working with the DNS. Another group of earlier
methods tries to build separate directory services for internationalized domain
names or keywords in local scripts. But these methods also require complex
implementation efforts, duplicating much of the work already done for the DNS.
Both the groups of earlier methods require creating internationalized domain
names or keywords in local scripts from scratch, which is a costly and lengthy
process on the parts of the DNS and Internet users. Further, domain names or
keywords created in local scripts are usable only by those who know the local
scripts, and so, they may segregate the Internet into many groups of different
sets of local scripts that are less universal than English scripts.
VIDN intends to provide a more immediate and less costly solution to
internationalized domain names than earlier methods. VIDN does not make any
change to the DNS nor require creating additional domain names in local scripts.
VIDN takes notice of the fact that many domain names currently used in regions
where English scripts are not widely used have their entity-defined portions
consisting of English scripts as transliterated from the respective local
scripts. Using this knowledge of transliteration between local and English
scripts, VIDN converts virtual domain names typed in local scripts into the
corresponding domain names in English scripts that comply with the DNS. In this
way, VIDN enables the same domain names to be used not only in English scripts
as usual but also in local scripts, without creating additional domain names in
local scripts.
4. VIDN method
4.1. Objectives
Earlier methods of internationalized domain names try to create domain names or
keywords in local scripts one way or another in addition to existing domain
names in English scripts, and put them inside or outside the DNS, using special
encoding schemes or lookup services. These methods require a lengthy and costly
process of creating domain names in local scripts and updating the DNS
components and applications. Even when they are successfully implemented, these
methods have a risk of localizing the Internet by segregating it into groups of
different sets of local scripts that are less universal than English scripts and
so diminishing the international scope of the Internet. Further, these methods
may cause more problems and disputes on copyrights, trademarks, and so on, in
local contexts than those that we experience with current domain names in
English scripts.
VIDN intends to provide a solution to the problems of earlier methods of
internationalized domain names. VIDN enables the same domain names to be used in
both English scripts as usual and local scripts, and so, there is no need to
create domain names in local scripts in addition to domain names in English
scripts. VIDN works automatically and transparently in applications at user
hosts before DNS requests are sent, and so, there is no need to make any change
to the DNS or to have additional name servers. For these reasons as well as
others, VIDN can be implemented more immediately with less cost than other
methods of internationalized domain names.
4.2. Description
It is important to note that most domain names used in regions where English
scripts are not widely used have their entity-defined portions consisting of
English scripts as transliterated from local scripts. Of course, there are many
domain names in those regions that do not follow this kind of transliteration
between local and English scripts. In such case, new domain names in English
scripts need to be created following this transliteration, but the number would
be minimal, compared to the number of internationalized domain names in local
scripts to be created and registered under other methods.
The English scripts transliterated from local scripts do not have any meanings
in English language, but their originals in local scripts before the
transliteration have some meanings in the respective local language, usually
indicating organization names, brand names, trademarks, and so on. VIDN enables
to use these original local scripts as the entity-defined portions of virtual
domain names in local scripts, by transliterating them into the corresponding
entity-defined portions of actual domain names in English scripts. In this way,
VIDN enables the same domain names in English scripts to be used virtually in
local scripts without actually creating domain names in local scripts.
As domain names in English scripts overlay IP addresses, so virtual domain names
in local scripts do actual domain names in English scripts. The relationship
between virtual domain names in local scripts and actual domain names in English
scripts can be depicted as:
+---------------------------------+
| User |
+---------------------------------+
| |
+----------------|-----------------------|------------------+
| v (Transliteration) v |
| +---------------------+ | +-----------------------+ |
| | Virtual domain name | | | Actual domain name | |
| | in local scripts |--+->| in English scripts | |
| +---------------------+ +-----------------------+ |
| User application | |
+----------------------------------------|------------------+
v
DNS requests
VIDN uses the phonemes of local and English scripts as a medium in
transliterating the entity-defined portions of virtual domain names in local
scripts into those of actual domain names in English scripts. This process of
transliteration can be depicted as:
Local scripts English scripts
+----------------------------+ +-----------------------------+
| Characters ----> Phonemes -----------> Phonemes ----> Characters |
| | | | | | |
| | | | | | |
| (Inverse of transcription) | Match | (Transcription) |
+----------------------------+ +-----------------------------+
| ^
| (Transliteration) |
+------------------------------------+
First, each entity-defined portion of a virtual domain name typed in local
scripts is decomposed into individual characters or sets of characters so that
each individual character or set of characters can represent an individual
phoneme of the local language. This is the inverse of transcription of phonemes
into characters. Second, each individual phoneme of the local language is
matched with an equivalent phoneme of English language that has the same or most
proximate sound. Third, each phoneme of English language is transcribed into the
corresponding character or set of characters in English language. Finally, all
the characters or sets of characters converted into English scripts are united
to compose the corresponding entity-defined portion of an actual domain name in
English scripts.
For example, a word in Korean language, '­­˜‚' that means 'century' in English
language, is transliterated into 'segi' in English scripts, and so, the entity
whose name contains '­­˜‚' in Korean language may have an entity-defined portion
of its domain name as 'segi' in English scripts. VIDN enables to use '­­˜‚' as
an entity-defined portion of a virtual domain name in Korean scripts, which is
converted into 'segi,' the corresponding entity-defined portion of an actual
domain name in English scripts. In other words, the phonemes represented by the
characters consisting of '­­˜‚' in Korean scripts have the same sounds as the
phonemes represented by the characters consisting of 'segi' in English scripts.
In the local context, '­­˜‚' in Korean scripts is clearly easier to remember and
type and more intuitive and meaningful than 'segi' in English scripts.
An entity-defined portion of a virtual domain name in Korean scripts, '¾ž®ý', is
transliterated into 'yahoo' in English scripts, since the phonemes represented
by the characters consisting of '¾ž®ý' in Korean scripts have the same sounds as
the phonemes represented by the characters consisting of 'yahoo' in English
scripts. That is, '¾ž®ý' in Korean scripts is pronounced as the same as 'yahoo'
in English scripts, and so, it is easy for Korean-speaking people to deduce '¾ž
®ý' in Korean scripts as the virtual equivalent of 'yahoo' in English scripts.
VIDN enables to use virtual domain names in local scripts for domain names whose
originals are in local scripts, e.g., '­­˜‚' in Korean scripts, as well as
domain names whose originals are in English scripts, e.g., '¾ž®ý' in Korean
scripts. In this way, VIDN is able to make domain names truly international,
allowing the same domain names to be used both in English and local scripts.
The coded portions of domain names such as generic codes and country codes can
also be transliterated from local scripts into English scripts, using their
phonemes as a medium. For example, seven generic codes in English scripts, 'com',
'edu', 'gov', 'int', 'mil', 'net', and 'org', can be transliterated from 'ýý', '
Àí´€', '—<>¦Š', 'ÁðË«', ' Ï', 'þÚË«', 'ÀÁ˜Ú' in Korean scripts, respectively,
which can be used as the corresponding generic codes of virtual domain names in
Korean scripts. Based upon its meaning in English language, each coded portion
of actual domain names also can be pre-assigned a virtual equivalent word or
code in local scripts. For example, seven generic codes in English scripts,
'com', 'edu', 'gov', 'int', 'mil', 'net', and 'org', can be pre-assigned '˜‚¾•'
(meaning 'commercial' in Korean language), 'ÌϘþ' (meaning 'education' in Korean
language), 'Âñ¦ð' (meaning 'government' in Korean language), '˜ Âª' (meaning
'international' in Korean language), '˜¦À‹' (meaning 'military' in Korean
language), 'þÚË«' (meaning 'network' in Korean language), and '³›È­' (meaning
'organization' in Korean language), respectively, which can be used as the
corresponding generic codes of virtual domain names in Korean scripts.
VIDN does not create such complexities as other conversion methods based upon
semantics do, since it uses phonemes as a medium of transliteration between
local and English scripts. Further, most languages have a small number of
phonemes. For example, Korean language has nineteen consonant phonemes and
twenty-one vowel phonemes, and English language has twenty-four consonant
phonemes and twenty vowel phonemes. Each phoneme of Korean language can be
matched with a phoneme of English language that has the same or proximate sound,
and vice versa.
Some characters or sets of characters may represent more than one phoneme. Some
phonemes may be represented by more than one character or set of characters.
Also, not every character or set of characters in local scripts may be neatly
transliterated into only one character or set of characters in English scripts.
In practice, people often transliterate the same local scripts differently into
English scripts or vice versa. VIDN incorporates the provisions to deal with
those variations that usually occur in particular situations as well as those
variations that are caused by common usage or idiomatic expressions. More
fundamentally, VIDN uses phonemes, which are very universal across different
languages, as a medium of transliteration rather than following a certain set of
transliteration rules that does not exist in many non-English-speaking countries
nor is followed by many non-English-speaking people.
One virtual domain name typed in local scripts may be converted into more than
one possible domain name in English scripts. In such case, VIDN can search for
and displays only those domain names in English scripts that are active on the
Internet, so that the user can choose any of them. Further, VIDN can be used as
a directory-search solution at an upper layer above the DNS. That is, the user
can use VIDN to query a phoneme-based domain name request in local scripts,
receive one or more corresponding domain names in English or ASCII-compatible
scripts preferably, choose one based upon the results of that search, and make
the final DNS request using any protocol or method to be chosen for
internationalized domain names. In this regard of directory search, VIDN uses
one-to-many map between virtual domain names in local scripts and actual domain
names in English scripts.
VIDN needs the one-to-many mapping and subsequent multiple DNS lookups only at
the first query of each virtual domain name typed in local scripts at the user
host. After the first query, the virtual domain name is set to the domain name
in English scripts that has been chosen at the first query. Any subsequent
queries with the same virtual domain name generate only one query with the
selected domain name in English scripts. Once the use selects one possible
domain name in English scripts from the list, VIDN remembers the user's
selection and directs the user to the same domain name at his or her subsequent
queries with that virtual domain name. In this way, VIDN can generate less
traffic on the DNS, while providing faster, easier, and simpler navigation on
the Internet to the user, using local scripts.
Utilizing a coding scheme, VIDN is also capable of making each virtual domain
name typed in local scripts correspond to exactly one actual domain name in
English scripts. In this coding scheme, a unique code such as the Unicode or
hexadecimal code represented by the virtual domain name, is pre-assigned to one
of the corresponding domain names in English scripts and stored in the
respective server host, so that both the user host and the server host can
support and understand the code. Then, VIDN checks whether the code at each
server host matches with the code generated at the user host. If one of the
servers stores the code that matches with the code generated at the user host,
the virtual domain name typed at the user host is recognized as corresponding
only to the domain name of that server host, and the user host is connected to
the server host. The domain names of the remaining server hosts that do not have
the matching code are also displayed at the user host as alternative sites.
Because a unique code is assigned to only one of the domain names in English
scripts, it does not cause any domain name squatting problem beyond what we
experience with current domain names in English scripts. Unique codes do not
need to be stored in any specific format, that is, they can be embedded in HTML,
XML, WML, and so on, so that the user host can interpret the retrieved code
correctly. Likewise, unique codes do not require any specific intermediate
transport protocol such as TCP/IP. The only requirement is that the protocol
must be understood among all participating user hosts and server hosts. For
security purpose, this coding scheme may use an encryption technique.
For example, 'ž¾Ô.ýý', a virtual domain name typed in Korean scripts, may
result in four corresponding domain names in English scripts, including
'jungang.com', 'joongang.com,' 'chungang.com', and 'choongang.com', since the
phonemes represented by characters consisting of 'ž¾Ô.ýý' in Korean scripts can
have the same or almost the same sounds as the phonemes represented by
characters consisting of 'jungang.com', 'joongang.com,' 'chungang.com', or
'choongang.com' in English scripts. In this case, we assume that the server host
with its domain name 'jungang.com' has the pre-assigned code that matches with
the code generated when 'ž¾Ô.ýý' in Korean scripts is entered in user
applications. Then, the user host is connected to this server host, and the
other server hosts may be listed to the user as alternative sites so that the
user can try them.
The process of this coding scheme that makes each virtual domain name in local
scripts correspond to only one actual domain name in English scripts, can be
depicted as:
+---------------------------------+
| User |
+---------------------------------+
| |
+----------------|-----------------------|------------------+
| v v |
| +---------------------+ +-----------------------+ |
| | Virtual domain name | | Potential domain names| |
| | in a local language |---->| in English | |
| | e.g., 'ž¾Ô.ýý' | | e.g., 'jungang.com' | |
| | (code: 297437)| | 'joongang.com' | |
| | | | 'chungang.com' | |
| | | | 'choongang.com' | |
| +---------------------+ +-----------------------+ |
| User application | |
+----------------------------------------|------------------+
^ |
| | Code check by VIDN
Connection to | | +-- 'jungang.com'
the server host | | | (code: 297437)
'jungang.com' | | |-- 'joongang.com'
| |----+ (not active)
| | |-- 'chungang.com'
| | | (code: 381274)
| DNS request and | +-- 'choongang.com'
| response | (not active)
+-----------------------+
Since VIDN converts separately the entity-defined portions and the coded
portions of a virtual domain name, it preserves the current syntax of domain
names, that is, the hierarchical dotted notation, which Internet users are
familiar with. Also, VIDN allows using a virtual domain name mixed with local
and English scripts as the user wishes to, since the conversion takes place on
each individual portion of the domain name and each individual character or set
of characters of the portion.
While VIDN preserves the hierarchical dotted notation of current domain names,
the principles of VIDN are applicable to domain names in other possible
notations such as those in a natural language (e.g., 'microsoft windows' rather
than 'windows.microsoft.com'). Also, the principles of VIDN can be applied into
other identifiers used on the Internet, such as user IDs of e-mail addresses,
names of directories and folders, names of web pages and files, keywords used in
search engines and directory services, and so on, allowing them to be used
interchangeably in local and English scripts, without creating additional
identifiers in local scripts. The conversion of VIDN can be done between any two
sets of scripts interchangeably. Thus, even when the DNS accepts and registers
domain names in other local scripts in addition to English, VIDN can allow using
the same domain names in any two sets of scripts by converting virtual domain
names in one set of scripts into actual domain names in another set of scripts.
4.3. Development and implementation
In a preferred arrangement, the development of VIDN for each set of local
scripts may be administered by one or more local standard bodies in regions
where the local scripts are widely used, for example, Korean Network Information
Center for Korean scripts, Japan Network Information Center for Japanese scripts,
and China, Hong Kong and Taiwan Network Information Centers for Chinese scripts,
with consultation with experts on phonemics and linguistics of the respective
local language and English language. Also, the unique codes for one-to-one
mapping between virtual domain names in local scripts and actual domain names in
English scripts can be administered by a central standard body like IANA.
Alternatively, the unique codes for each set of local scripts may be
administered by one or more local standard bodies in regions where the local
scripts are widely used, as with the development of VIDN.
VIDN is implemented in applications at the user host. That is, the conversion of
virtual domain names in local scripts into the corresponding actual domain names
in English scripts takes place at the user host before DNS requests are sent.
Thus, neither a special encoding nor a separate lookup service is needed to
implement VIDN. VIDN is also modularized with each module being used for
conversion of virtual domain names in one set of local scripts into the
corresponding actual domain names in English scripts. A user needs only the
module for conversion of his or her preferred set of local scripts into English
scripts. Alternatively, VIDN can be implemented at a central server host or a
cluster of local server hosts. A central server can provide the conversion
service for all sets of local scripts, or a cluster of local server hosts can
share the conversion service. In the latter case, each local server host can
provide the conversion service for one or more sets of local scripts used in a
certain region.
Because of its small size, VIDN can be easily embedded into applications
software such as web browser, e-mail software, ftp system, and so on at the user
host, or it can work as an add-on program to such software. In either case, the
only requirement on the part of the user is to install VIDN or software
embedding VIDN at the user host. Using virtual domain names in local scripts in
accordance with the principles of VIDN is very intuitive to those who use the
local scripts. The only requirement on the part of the entity whose server host
provides Internet services to user hosts is to have an actual domain name in
English scripts into which virtual domain names in local scripts are neatly
transliterated in accordance with the principles of VIDN. Most entities in
regions where English scripts are not widely used already have such domain names
in English scripts. Finally, there is nothing to change on the part of the DNS,
since VIDN uses the current DNS as it is.
Taken together, the features of VIDN can meet all the requirement of
internationalized domain names as described in Wenzel and Seng [2], with respect
to compatibility and interoperability, internationalization, canonicalization,
and operating issues. Given the fact that different methods toward
internationalized domain names confuse users, as already observed in some
regions where some of these methods have already been commercialized, e.g.,
Korea, Japan and China, it is important to find and implement the most effective
solution to internationalized domain names as soon as possible.
4.4. Current status
VIDN has been developed for Korean-English conversion as a web browser add-on
program. The program contains all the features described in this document and is
capable of listing all the domain names in English scripts that correspond to a
virtual domain name typed in Korean scripts so that a user can choose any of
them. The program can cover more than ninety percent of the sample. That is, the
results of testing indicate that more than ninety percent of web sites in Korea
can be accessed using virtual domain names in Korean scripts without creating
additional domain names in Korean scripts. The remaining ten percent of domain
names are mostly those that contain acronyms, abbreviations or initials. With
improvement of its knowledge of transliteration, the program is expected to
cover more domain names used in Korea.
5. Security considerations
Because VIDN uses the DNS as it is, it inherits the same security considerations
as the DNS.
6. Intellectual property considerations
It is the intention of DualName, Inc. to submit the VIDN method and other
elements of VIDN software to IETF for review, comment or standardization.
DualName has applied for one or more patents on the technology related to
virtual domain name software and virtual email software. If a standard is
adopted by IETF and any patents are issued to DualName with claims that are
necessary for practicing the standard, DualName is prepared to make available,
upon written request, a non-exclusive license under fair, reasonable and non-
discriminatory terms and condition, based on the principle of reciprocity,
consistent with established practice.
7. References
1 Wenzel, Z. and Seng, J. (Editors), "Requirements of Internationalized Domain
Names," draft-ietf-idn-requirements-03.txt, August 2000
8. Author's address
Sung Jae Shim
DualName, Inc.
3600 Wilshire Boulevard, Suite 1814
Los Angeles, California 90010
USA
Email: shimsungjae@dualname.com
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